This research program investigates the mechanism of action of selected genetic and environmental factors on experimental atherosclerosis in the infant and juvenile baboon (Papio cynocephalus). Three experiments examine the effects of infant nutrition (formula cholesterol content, caloric intake, and salt intake) on serum lipids, blood pressure, and experimental atherosclerosis in adulthood. Three experiments estimate heritability of control of serum cholesterol and lipoproteins, search for monogenic variants, and seek enhancing characters related to atherosclerosis by selective breeding and hybridization. One project investigates the role of intestinal microflora in regulation of cholesterol metabolism by surveying the microflora of the baboon intestinal tract and studies cholesterol metabolism in the gnotobiotic baboon by introducing known bacteria. Two projects study the effects of cigarette smoke inhalation on experimental atherosclerosis and pulmonary function and structure in baboons trained to puff on cigarettes and inhale cigarette smoke. Two projects relate hypertension and antihypertensive therapy to atherogenesis. By observing baboon behavioral characteristics in three of the above described experiments, we are searching for associations between behavioral variables and susceptibility to atherosclerosis. The research program is supported by core laboratories in lipid biochemistry, behavior, pathology, veterinary services, and biometry.